The basic structure of an organic electroluminescent device (e.g. OLED) includes an anode layer, a cathode layer and a “luminescent layer” sandwiched between the anode layer and the cathode layer, wherein the luminescent layer includes one or more organic layers. Under the action of an external voltage, electrons and holes are respectively injected into the organic layers from the cathode and the anode and then migrated and compounded in the “luminescent layer” to produce excitons, and the energy of the excitons is attenuated in the form of light, namely light is radiated.
In the luminescent process of the organic electroluminescent device, energy loss is mainly on two aspects. First, when injected carriers emit light by coupling in the luminescent layer, not all injected energy is transformed into photons, a part of energy of the excitons is lost by a non-radiative transition process such as lattice vibration or deep-level impurity transition, and this process may be described with internal quantum efficiency. Second, only about 20% of light emitted from the luminescent layer may penetrate through the device to enter air after passing through above multilayer structures and is seen due to total reflection occurring on the interfaces between the anode layer and a base of the organic electroluminescent device, between the base and air and the like, a waveguide mode occurring on the interface between the anode layer and the luminescent layer of the organic electroluminescent device, surface plasma loss nearby metal electrodes and the like.
As shown in FIG. 1, an organic electroluminescent display panel includes a color filter substrate and an array substrate subjected to cell aligning, gaps formed after cell aligning of the color filter substrate and the array substrate are filled with an adhesive layer 300, color filters 101 and black matrixes 102 are arranged on a first base 100 of the color filter substrate, and organic electroluminescent devices (which are obtained by defining an organic electroluminescent material layer 201 with a pixel defining layer 202) are arranged on a second base 200 of the array substrate. Due to the loss of energy in the luminescent process of the organic electroluminescent device, the light output efficiency of the organic electroluminescent device is low, then the light output efficiency of the organic electroluminescent display panel is low, and the display effect is poor.